Method of preparing cleansing compositions



United States Patent M 3,303,135 METHOD OF PREPARING CLEANSING COMPOSITIQNS Seymore Goldwasser, Teaneck, N.J., assignor to Lever Ilag-others Company, New York, N.Y., a corporation of awe No Drawing. Filed Jan. 25, 1965, Ser. No. 427,971 9 Claims. (Cl. 252137) This is a continuation-in-part of my co-pending application Serial No. 97,178, filed March 21, 1961, now abandoned.

This invention relates to the manufacture of cleansing compositions and, more particularly, to a method of incorporating a brightening agent in a heat-dried cleansing composition.

The incorporation of brightening agents into cleansing compositions is known. These agents are in the nature of fluorescent dyes which flouresce white when subjected to a source of ultraviolet light such as sunlight. Fabrics which are treated with compositions containing such brighteners appear to be whiter than fabrics which are not so treated. Thus, cleansing compositions are apt to be more acceptable to the consumer where the materials which are washed with the cleanser exhibit a whitened or bleached effect.

The compound alphazbeta-di-[S-rnethyl-benzoxazolyl- (2)]-ethylene'has been suggested as a brightening agent and is the active agent in the commercially available brightener Uviter K. In U.S. Patent No. 2,873,206, there is disclosed a process for the optical brightening of polyester fibers with an aqueous dispersion of the above-named compound using a nonionic surface active agent as the dispersion agent followed by heat treatment to obtain the desired fluorescent effect.

Attempts to incorporate the above-named whitening agent into a detergent composition which is ultimately heat-dried by adding the agent to the detergent paste in the crutcher without pausing between the addition of successive compounds have met with failure. Not only was no fluorescence obtained when the paste was heatdried, but also the finished powder was severely discolored. The problem has been to protect the whitening agent from agglomeration, crystallization, or other change in state which prevents the agent from being effective, while at the same time maintaining a condition in which the agent is readily absorbed on textile materials.

A method has now been found to incorporate the above-named whitening agent into a heator spray-dried detergent composition without encountering the difficulties enumerated above. It has been discovered that the problem may be solved by the process described below in which the optical brightener is affixed to a cellulosic material, particularly sodium carboxymethylcellulose, in such a manner as to prevent a change to the inactive state and yet readily permit transfer to a textile material.

Briefly, the method according to the present invention comprises adding a dispersion of the above-mentioned optical brightener to the carboxymethylcellulose (CMC), water, and sodium silicate normally employed in the conventional detergent formulation, and agitating the mixture for at least three minutes to assure aflixation of the brightening agent to the CMC carrier. The other normal ingredients of the detergent formulation, including a nonionic surface active agent, sequestering agents, fillers, coloring agents, etc. may then be added. After further agitation to insure proper blending, the mixture is heat-dried to form a detergent powder.

While the present invention is not to be limited to any 3,303,135 Patented Feb. 7, 1967 patricular theory, it will be evident from the foregoing that an essential step in this invention is to preblend the optical brightener and CMC. It has been found that by pre-blending these two ingredients of the detergent formulation, the optical brightener is aflixed or adsorbed onto the CMC. The latter acts as a carrier to maintain the optical brightener in an active state and to permit it to be readily transferred to the textile material when the detergent is used. To aid in the affixation of the optical brightener to the CMC, it is helpful to also incorporate the liquid ingredients of the detergent formulation, namely, water and sodium silicate, during the pre-blending step.

As used in this specification and in the appended claims, the phrase nonionic surface active agent refers to those compounds commonly recognized in the detergent industry as being nonionic surfactants having detergent properties. All such nonionic surface active agents may be used. More specifically, the term nonionic surface active agents is used commercially to refer to condensates of ethylene oxide or propylene oxide with alcohols, phenols or derived alcohols (i.e. alcohols containing a terminal OH group together with other functional groups such as another hydroxyl group, ether linkages, ester linkages, amides, etc.).

Specific detergents which may be mentioned are block polymers of ethylene oxide and propylene oxide, condensates of ethylene oxide with alkyl phenols containing from 6 to 20 carbon atoms in the alkyl group, and condensates of ethylene or propylene oxide with fatty alcohols containing from 6 to 20 carbon atoms. In the foregoing detergent compounds, the ethylene or propylene oxide condensates may contain from 1 to 15 alkylene oxide units.

Typical commercially available compounds of the foregoing general description include, but are not limited to, polyoxyethylene-polyoxpropylene ethanols prepared by condensing ethylene oxide with a hydrophobic base formed by the condensation of propylene oxide with propylene glycol having the empirical formula where b is an integer from 26 to 30. A variety of detergents are available in which a plus c are integers such that the molecule might contain less than 10% ethylene oxide, or from 10% to 20% ethylene oxide, or from 20% to 30% ethylene oxide, etc., up to about ethylene oxide. (The weight percentages are based on the weight of the total molecule.) The foregoing class of compounds has a polyoxypropylene hydrophobic base whose molecular weight is about 1750. Like condensates in which the hydrophobic base has a molecular weight ranging from about 950 to 3250 are also available.

Still another group of commercially available compounds is formed by condensing one mole of a phenol with from 1 to 15 moles of ethylene oxide. Phenols yielding surfactants having detergent properties usually contain an alkyl group having from 6 to 20 carbon atoms. In this group of compounds the length of the polyoxyethylene chain controls the hydrophilic character of the detergent. The most desirable materials generally will have from about 5 to about 10 moles of ethylene oxide for each mole of alkyl phenol, such as the nonyl phenol-9 ethylene oxide condensate and dodecyl phenol- 10 ethylene oxide condensate.

The condensates of phenols and ethylene oxide tend to give more suds than may be desired in a commercial controlled sudsing detergent. For the purpose of controlling sudsing in such a detergent, therefore, it may be desired to employ a polyoxyethylene-polyoxypropylene ethanol block polymer in combination with the phenolethylene oxide condensate. Polyoxyethylene-polyoxy- 3 propylene ethanols useful for controlling the suds level usually contain less than about 10% ethylene oxide.

Still another class of compounds commercially available is formed by condensing ethylene oxide with alkyl alcohols containing from 8 to 20 carbon atoms. The alkyl alcohols may be derived from natural sources, e.g. the condensate formed by condensing one mole of coconut fatty alcohols with from 5 to 15 moles of ethylene oxide. Alcohols of this character may also be obtained by synthetic methods adapted to provide a fatty alcohol having a primary hydroxy group. As mentioned, the desired alcohols may contain other substituent groups. Typical compounds are the condensate of lauryl alcohol with 5 moles of ethylene oxide and the condensate of stearyl alcohol with 12 moles of ethylene oxide.

The sodium silicate used in this invention is of the type generally employed in commercial detergent formulations for the purpose of corrosion inhibition. Typically, the sodium silicate will have a ratio of N21 O:SiO of about 1:24. However, the nature and description of the sodium silicate is not critical. Any sodium silicate adapted for conventional use in detergent formulations may be employed in the practice of the present invention. As already mentioned, it is desirable to add the sodium silicate to the detergent formulation at the time of pre-blending the CMC and optical brightener merely for the purpose of imparting fluidity to the pre-blended materials and thereby to assist in adsorbing the optical brightener onto the CMC.

The sequestering agents which are employed are of the condensed phosphate type. More specifically, these are the alkali metal pyrophosphate and alkali metal polyphosphates. For obvious commercial reasons, the sodium and potassium salts are preferred, and, it is also generally preferred to employ the tripolyphosphates rather than the pyrophosphates.

The carboxymethylcellulose which is employed as a carrier in the present invention is of the type commonly recognized in the detergent industry as being useful as a soil suspending agent.

As optional ingredients, the usual colorants, perfumes, fillers, etc. may be added to the detergent formulation. In this connection, it is noted that sodium sulfate is commonly employed in amounts up to 25% to 30% of the detergent formulation as a filler. Also contemplated as an optional ingredient is the inclusion of a second optical bn'ghtener to be used in conjunction with the alpha :beta-di- [S-methyl-benzoxazolyl- 2) J-ethylene.

In the practice of this invention, the ratio of carboxymethylcellulose to alphaz'beta-di-[S-methyl-benzoxazolyl- (2)]-ethy1ene is not critical. The amount of carboxymethylcellulose which would normally be employed in a detergent formulation is sufiicient adequately to disperse and to stabilize the optical brightener. Effective stabilization of the optical brighter has been obtained using a ratio of CMC to optical brightener of about 8:1 or greater. (In the foregoing, ratios in parts by weight are referred to.)

The amounts of water and sodium silicate relative to the amount of carboxymethylcellulose and optical brightener is likewise not critical. Whatever amount of water is normally employed in the detergent preparation for the purpose 'of aiding the bending of the final composition prior to spray. drying will be more than adequate to permit satisfactory adsorption of the optical brightener onto the CMC. Likewise, and for the same reasons, the amount of sodium silicate which is conventionally 'employed in the detergent formulation (i.e. in the order of 0.1 to 20%) may be used. As already mentioned, water and sodium silicate are employed during the preblending step merely for the purpose of aiding the afiixation of the optical brightener to the CMC. Mainifestly, in a completely dry mixture, adsorption sufficient to provide effective stabilization would be obtained only With the greatest of difficulty. Accordingly, it is desir- 4 able to add some or all of the fluid ingredients of the formulation at the time of pre-blending the optical brightener and CMC.

Example 1 To a standard crutcher was added 513.0 pounds of water and 100.0 pounds of sodium silicate (46.8% solids). Agitation of this mixture was begun as 5.33 pounds of sodium carboxymethylcellulose (75% active) was added. After three minutes, 0.66 pound of Uvitex K (alpha beta-di- S-methyl-benzoxazolyl- (2) -ethylene) dispersed in four times its weight of Carbitol was added and agitation was continued for three additional minutes. After the addition of 1.374 pounds of triazinyl fluorescent dye ('65.5% active) dispersed in three times its weight of hot water, agitation was stopped. pounds of the condensate of dodecylphenol with 10 moles of ethylene oxide and 10 pounds of a polyoxyethylenepolyoxypropylene ethanol of the formula in which b is between about 24 and about 30, and a plus c are integers such that the compound contains less than about 10% ethylene oxide, were then added and agitation again commenced. The slurry temperature at this point was to F. 400 pounds of pentasodium tripolyphosphate was carefully added at a rate which did not overload the crutcher and stop the agitators. 306 pounds of sodium sulphate was added after thickening of the slurry had occured. At this point, the slurry temperature may be adjusted to obtain proper gravit control.

The slurry was pumped to a booster tank and then to a spray-drying tower where it was heat-dried. This formula yieldedabout 1,000 pounds of finished powder.

Example 2 Employing the general procedure outlined in Example 1, a detergent was prepared in accordance with the following formulation.

Pre-blend: Pounds Water 513.0 Sodium silicate (46.8% solids) 100 CMC (75% active) 5.33 Optical Brightener 1 0.2

After pre-blending, add:

Alfonic 1418-6 2 90 Sodium tripolyphosphate 400 Sodium sulfate 306 Alpha beta di-[ti-methyl benzoxazo1yl-(2)]-ethylene dispersed in four times its weight in Carbitol.

A condensate of a mixed Cir-C1 fatty alcohol with ethylene oxide, containing 60% ethylene oxide in the condensate.

Example 3 Following the general procedure outlined in Example 1, a detergent formulation was prepared in accordance with the following.

1 Alpha be'ta-di-[5methyl-benz-oxaz'olyl-(2)] ethylene dispersed in four times its weight in Carbitol.

A block polymer prepared by condensing ethylene oxide Wlfh a hygrophttilbie basle formed 1b% the condensation of propy ene 0x1 e W1 propy ene g yco aving the general formula HO(C2H,,O) 11(C3H50) b(C2H4O)c--H Where b is an integer between 26 and 30 and a plus a are integers such that the molecule contains about 40% ethylene oxide.

Example 4 To a standard crutcher was added 513.0 pounds of water and 100.0 pounds of sodium silicate (46.8% solids). Agitation of this mixture was begun as 5.33 pounds of sodium carboxymethylcellulose (75% active) was added. After three minutes, 0.06 pound of Uvitex K (alphazbetadi-[S-methyl-benzoxazolyl (2)] ethylene) dispersed in four times its weight of Carbitol was added and agitation was continued for three additional minutes. After the addition of 1.374 pounds of triazinyl fluorescent dye (65.5% active) dispersed in three times its weight of hot water, agitation was stopped. 80 pounds of the condensate of dodecylphenol with moles of ethylene oxide and 10 pounds of a polyoxyethylene-polyoxypropylene ethanol of the formula in which b is between about 24 and about 30, and a plus 0 are integers such that the compound contains less than about 10% ethylene oxide, where then added and agitation again commenced. The slurry temperature at this point was 120 to 130 F. 400 pounds of pentasodium tripolyphosphate was carefully added at a rate which did not overload the crutcher and stop the agitators. 306 pounds of sodium sulphate was added after thickening of the slurry had occurred. At this point, the slurry temperature may be adjusted to obtain proper gravity control.

The slurry was pumped to a booster tank and then to a spray-drying tower where it was heat-dried. This formula yielded about 1,000 pounds of finished powder.

It will be understood that the above-described embodiments of the invention are illustrative only and that modifications will occur to those skilled in the art. Therefore, the invention is not to be limited to the specific ingredients and proportions thereof mentioned in the foregoing examples.

I claim:

1. In the preparation of a heat-dried nonionic detergent composition consisting essentially of (a) at least one nonionic surface active agent having detergent properties, (b) a phosphate builder selected from the group consisting of alkali metal pyrophosphates and alkali metal tripolyphosphates in an amount sufficient to improve the detergency of said surface active agent, (c) sodium carboxymethylcellulose in an amount effective to impart soil suspending properties to said composition, and (d) sodium silicate in an amount effective to inhibit corrosion, said composition being prepared by blending the aforesaid ingredients with water to prepare a slurry, and heat-drying the resultant slurry; the improvement comprising combining said carboxymethylcellulose, water and sodium silicate with alpha:beta-di-[S-methyl-benzoxazoly1-(2)]-ethylene as a brightening agent, and agitating said mixture for at least three minutes to affix said brightening agent to said carboxymethylcellulose, the amount of said carboxymethylcellulose relative to said brightening agent being sufiicient to adsorb said dye and to maintain it in an active state, and subsequently blending therewith said nonionic surface active agent and said phosphate and heat-drying the resulting slurry.

2. A process according to claim 1 wherein said condensate of a phenol with ethylene oxide is dodecylphenol condensed with ethylene oxide in a mole ratio of 1:10.

3. In the preparation of heat-dried nonionic detergent compositions consisting essentially of (a) a combination having detergent properties of a condensate of phenol with ethylene oxide and a polyoxyethylene-polyoxypropylene ethanol containing less than about 10% ethylene oxide in the molecule, (b) a phosphate builder selected from the group consisting of alkali metal pyrophosphates and alkali metal polyphosphates in an amount suflicient to improve the detergency thereof, (c) sodium carboxymethylcellulose in an amount effective to impart soil suspending properties to said composition and (d) sodium silicate in an amount effective to inhibit corrosion, said composition being prepared by blending the aforesaid ingredients with Water to prepare a slurry and heatdrying the resultant slurry; the improvement which comprises combining said carboxymethylcellulose, water, and sodium silicate with alpha:beta-di-[S-methyl-benzoxazolyl-(2)]-ethylene as a brightening agent and agitating said mixture for at least three minutes to affix said brightening agent to said carboxymethylcellulose, the amount of said carboxymethylcellulose relative to said brightening agent being sufficient to adsorb said brightening agent and to maintain it in an active state, and subsequently blending therewith said condensate of phenol with ethylene oxide, said polyoxyethylene-polyoxypropylene ethanol and said phosphate, and heat-drying the resulting slurry.

4. The process according to claim 3 wherein the phosphate is pentasodium tripolyphosphate.

5. In the preparation of heat-dried nonionic detergent compositions consisting essentially of (a) a polyoxyethylene-polyoxypropylene ethanol block polymer having detergent properties in which the polyoxypropylene group has a molecular weight between about 950 and 3250 and in which the block polymer contains between about 10% to about ethylene oxide, (b) a phosphate selected from the group consisting of alkali metal pyrophosphates and alkali metal tripolyphosphates in an amount suflicient to improve the detergency thereof, (c) sodium carboxymethylcellulose in an amount effective to impart soil suspending properties to said composition, and (d) sodium silicate in an amount effective to inhibit corrosion, said composition being prepared by blending the aforesaid ingredients with water to prepare a slurry and heatdrying the resultant slurry; the improvement which comprises combining said carboxymethylcellulose, water and sodium silicate with alapha:beta-di-[S-mcthyl-benzoxazolyl-(Z)]-ethylene as a brightening agent, and agitating said mixture for at least three minutes to afiix said brightening agent to said carboxymethylcellulose, the amount of said carboxymethylcellulose relative to said brightening agent being suflicient to adsorb said brightening agent and to maintain it in an active state, and subsequently adding thereto said polyoxyethylene-polyoxypropylene ethanol and said phosphate, and heat-drying the resulting slurry.

6. In the preparation of heat-dried nonionic detergent compositions consisting essentially of (a) a condensate of ethylene oxide with a phenol having detergent properties, (b) a phosphate selected from the group consisting of alkali metal pyrophosphates and alkali metal tripolyphosphates in an amount sufficient to improve the detergency thereof, (c) sodium carboxymethylcellulose in an amount effective to impart soil suspending properties to said composition, and (d) sodium silicate in an amount effective to inhibit corrosion, said composition being prepared by blending the aforesaid ingredients with water to prepare a slurry and heat-drying the resultant slurry; the improvement which comprises combining said carboxymethylcellulose, water and sodium silicate with alpha beta-di- [S-methyl-benzoxazolyl- (2) j-ethylene as a brightening agent and agitating said mixture for at least three minutes to affix said brightening agent to said carboxymethylcellulose, the amount of said carboxymethylcellulose relative to said optical brightener being sufficient to adsorb said optical brightener and to maintain it in an active state and subsequently adding thereto said condensate of ethylene oxide and a phenol and said phosphate and heat-drying the resulting slurry.

7. In the preparation of heat-dried nonionic detergent compositions consisting essentially of (a) a condensate having detergent properties of ethylene oxide with an alkyl alcohol containing from 8 to 20 carbon atoms, (b) a phosphate selected from the group consisting of alkali metal pyrophosphate and alkali metal tripolyphosphate in an amount sufiicient to improve the detergency thereof, (c) carboxymethylcellulose in an amount effective to impart soil suspending properties to said composition, and (d) sodium silicate in an amount effective to inhibit corrosion, said composition being prepared by blending the aforesaid ingredients with water to prepare a slurry and heat-drying the resultant slurry; the improvement comprising combining said carboxymethylcellulose, water and sodium silicate with alphazbeta-di-[S- methyl-benzoxazolyl-(2)]-ethylene as a brightening agent and agitating said mixture for at least three minutes to afiix said brightening agent to said carboxymethylcellulose, the amount of said carboxymethylcellulose relative to said brightening agent being sufiicient to adsorb said optical brightener and to maintain it in an active state,

and subsequently blending therewith said condensate of ethylene oxide with an alkyl alcohol, and said phosphate, and heat-drying the resulting slurry.

8. In the preparation of heat-dried nonionic detergent compositions consisting essentially of (a) at least one nonionic surface active agent having detergent properties,

prising combining said carboxymethylcellulose, water and sodium silicate with alpha:beta di-[5-methyl-benzoxazolyl-(2)]-ethy1ene as a brightening agent and agitating said mixture for at least three minutes to afiix said brightening agent to said carboxymethylcellulose, there being at least eight parts by weight of said carboxymethylcellulose for each part of said brightening agent and subsequently blending therewith said nonionic surface active agent and said phosphate and heat-drying the resulting slurry.

9. The process according to claim 8 in which the nonionic surface active agent is a combination having detergent properties of a condensate of one mole of dodecylphenol With 10 moles of ethylene oxide and a 'polyoxyethylene-polyoxypropylene ethanol-containing less than about 10% ethylene oxide in the'molecule.

References Cited by the Examiner UNITED STATES PATENTS 1,979,469 11/1934 Johnson 8.79 2,146,755 2/1939 McNally et a1. 891 2,870,093 1/1959 Ruff 252-137 2,873,206 2/1959 Geigy et a1. 252302 3,047,353 7/1962 Klein 862 LEON D. ROSDOL, Primary Examiner.

JULIUS GREENWALD, Examiner. I. T. FEDIGAN, Assistant Examiner. 

1.IN THE PREPARATION OF A HEAT-DRIED NONIONIC DETERGENT COMPOSITION CONSISTING ESSENTIALLY OF (A) AT LEST ONE NONIONIC SURFACE ACTIVE AGENT HAVING DETERGENT PROPERTIES, (B) A PHOSPHATE BUILDER SELECTED FROM THE GROUP CONSISTING OF ALKALI METAL PYROPHOSPHATES AND ALKALI METAL TRIPOLYPHOSPHTES IN AN AMOUNT SUFFICIENT TO IMPROVE THE DETERGENCY OF SAID SURFCE ACTIVE AGENT, (C) SODIUM CARBOXYMETHYLCELLULOSE IN AN AMOUNT EFFECTIVE TO IMPART SOIL SUSPENDING PROPERTIES TO SAID COMPOSITION, AND (D) SODIUM SILICATE IN AN AMOUNT EFFECTIVE TO INHIBIT CORROSION, SAID COMPOSITION BEING PREPARED BY BLENDING THE AFORESAID INGREDIENTS WITH WATER TO PREPARE A SLURRY, AND HEAT-DRYING THE RESULTANT SLURRY; THE IMPROVEMENT COMPRISING COMBINING SAID CARBOXYMETHYLCELLULOSE, WATER AND SODIUM SILICATE WITH ALPHA:BETA-DI-(5-METHYL-BENZOXAZOLYL-(2))-ETHYLENE AS A BRIGHTENING AGENT, AND AGITATING SAID MIXTURE FOR AT LEAST THREE MINUTES TO AFFIX SAID BRIGHTENING AGENT TO SAID CARBOXYMETHYLCELLULOSE, THE AMOUNT OF SAID CARBOXYMETHYLCELLULOSE RELATIVE TO SAID BRIGHTENING AGENT BEING SUFFICIENT TO ADSORB SAID DYE AND TO MAINTAIN IT IN AN ACTIVE STATE, AND SUBSEQUENTLY BLENDING THEREWITH SAID NONIONIC SURFACE ACTIVE AGENT AND SAID PHOSPHATE AND HEAT-DRYING TGHE RESULTING SLURRY. 